Objective To study the antidepressant functional target of Shuyu Capsule（ 舒郁胶囊） and its related mechanism. Methods Fifty Wistar rats were randomly divided into normal group

model group

Shuyu Capsule group

fluoxetine group and WAY-100635 group

10 in each. Depression model was made by 28-day chronic mild stress. During the modeling period

the Shuyu Capsule group was given Shuyu Capsule 0. 51 g /（ kg·d）

with the flu-oxetine group giving Fluoxetine Capsule 2 × 10- 3g /（ kg·d）

WAY-100635 group giving WAY-100635 0. 2 × 10- 3g /（ kg·d）

and equivalent normal saline was given to normal and model group. Body weight

open field test total score and the sucrose preference coefficient in each group were recorded before and after modeling and interventions. After modeling

6 rats in each group were picked to measure the expression of 5-hydroxytrytamine 1A receptor（ 5-HTR1A）and the phosphorylation level of c AMP response element binding（ CREB） in gastric and intestinal tissue by western blot

and the cyclic adenosine monophosphate（ c AMP） was detected by ELISA. Results Compared with normal group

the body weight

open field test total score and sucrose preference coefficient in model group decreased significantly（ P < 0. 01）

meanwhile these indicators in Shuyu Capsule group and fluoxetine group were higher significantly（ P < 0. 05 or P < 0. 01）. Compared with normal group

much more 5-HTR1 A in gastric and intestinal tissue was expressed in model group

and much less c AMP and CREB phosphorylation was expressed（ P < 0. 05 or P < 0. 01）.Shuyu Capsule and WAY-100635 could remarkably lower the relative expression of 5-HTR1 A in murine gastric and intestinal tissue and improve c AMP and CREB phosphorylation（ P < 0. 05 or P < 0. 01）. Fluoxetine can upregulate the c AMP in murine gastric and intestinal tissue and enhance CREB phosphorylation in murine gastric tissue（ P < 0. 05 or P < 0. 01）. Conclusion Shuyu Capsule seems to perform the antidepressant function by down-regulating the expression of 5-HTR1 A in gastric and intestinal tissue as well as up-regulating c AMP and CREB phosphorylation in its downstream signaling pathway.